RockyMtnMT
Official LRH Sponsor
I didn't. I patented radius bands on bullets.
Parabolic Drag
- Thread starter RockyMtnMT
- Start date
Help Support Long Range Hunting Forum
cohunt
Well-Known Member
My umbrella collapses way before transonic or mach 1--- maybe I need a higher quality umbrella?
Ok, I'm a bit scared to ask this because you very well may be able to answer it, which in turn means I will be obligated to read said answer and then I will need another drink, but how do you solve an equation on lift or drag when an object is in a vacuum? Aren't lift and drag absent in a vacuum?
Give me a couple minutes while I grab the Whistlepig and a glass!
JakeC
Well-Known Member
I'm from lobster fishing country, we recommend Grundens for this situation and nothing else.
JakeC
Well-Known Member
How is whistlepig, what's it similar to? It's one of the few stops I never got off on when I lived in a state with real selection.
I like them quite a bit. Tonight was 15 year, but every one is delicious. I was gifted a 18 year, but haven't worked up the nerve to open it yet. The 10 & 12 year are the sweet spot for price/drinkability. If you like a rye Old Fashioned the 6 year Piggyback is great. they are very smooth rye whiskeys with good notes and not just overly spicy.
Bob Wright
Well-Known Member
Steve,
Try reading this article and pay attention to the hyper-links regarding Bryan Litz' articles on drag, towards the end of the article.
Bullets that have grooves or drive bands might be covered there.
You might call or message Bryan if there are questions not answered in the links.
A CNC machined bullet certainly has consistencies unmatched vs cup and core which is helpful. After that, you need Bryan or an aero dynamics study.
Personalized Drag Models: The Final Frontier in Ballistics?
I am super-excited about this article! I've actually been working on it for a couple of months, and...
dfanonymous
Well-Known Member
- Joined
- Jul 16, 2016
- Messages
- 2,271
Haha
There are equations, but it's easier to speak plainly that your gripe with what I said is, correct.
Air craft that require lift cannot fly in a perfect vacuum, technically. I was over simplifying it to keep on track of my point.
To your question and more to my point, what I was referring to but not elaborating on, is partial vacuum. Think of a spy aircraft R&D trying to reach say, 100 km.
JakeC
Well-Known Member
Ooh nice. I do like a rye. The best I can get right now is High Plains from nearby in Park City. They're a reliable blender/bottler but they tend toward wide open throttle and 6-8 years as far as I can tell. Thanks. Hijack over.
Buckys
Well-Known Member
Steve,
Generally, a lot of analysis on drag is part of "fluid dynamics" ... a projectile spinning through the air at 3000+ fps is a concern of fluid (air) dynamics.
How you model drag is a function of lots of things including the chaos/turbulence of the fluid flow.
When we tried to design airplanes that could break the sound barrier, for example, we found that the drag models used for sub-sonic flight were not adequate to model the drag at supersonic speeds.
Here is an university class introducing students to the concepts related to drag:
Generally, a lot of analysis on drag is part of "fluid dynamics" ... a projectile spinning through the air at 3000+ fps is a concern of fluid (air) dynamics.
How you model drag is a function of lots of things including the chaos/turbulence of the fluid flow.
When we tried to design airplanes that could break the sound barrier, for example, we found that the drag models used for sub-sonic flight were not adequate to model the drag at supersonic speeds.
Here is an university class introducing students to the concepts related to drag:
This is the first thing I've heard that makes sense thank you
shootski
Well-Known Member
I flew for the US Navy and never ran into any Parabolic Drag until I went Clubbing!
That's where I found lots of it on Beer Bellied guys trying to hit on the women.
That's where I found lots of it on Beer Bellied guys trying to hit on the women.
JakeC
Well-Known Member
Some navy vets have told me there's a lot of parabolic drag in the asian ports.
WildCard
Member
Steve,
Simply put, the link you shared is describing the relationship between lift and drag for an airfoil over a range of angles of attack; the relationship is parabolic. That is, as angle of attack goes up from zero, lift increased faster than drag for a short time, then drag starts to increase much more quickly than lift. Instead of plotting lift against angle of attack and then drag against angle of attack, they plotted lift and drag (coefficients) against one another, which is much less intuitive to follow.
Try it for yourself if you like: put your open hand out the window of your car while driving, and hold it flat. You feel a little bit of drag and no lift. Now start rotating your thumb upwards relative to your pinkie finger. At first you start to feel your hand want to rise (lift), with only a little more force backwards (drag). By the time you get your palm facing into the wind, your hand is producing only drag, with no lift. The relationship of lift to drag you just felt is parabolic - once you rotated your hand too far, it slowly stopped producing more lift and rapidly started producing more drag.
Hope that made sense and helps. While drag is obviously important to bullets, we generally are not trying to produce lift, so this topic may not be especially relevant to your goals as a bullet maker...
